﻿	using System;
	using System.Runtime.InteropServices;
	using System.Xml.Serialization;

namespace ReaderUtils
{
		/// <summary>
		/// Represents a 3D vector using three single-precision floating-point numbers.
		/// </summary>
		/// <remarks>
		/// The Vector3 structure is suitable for interoperation with unmanaged code requiring three consecutive floats.
		/// </remarks>
		[Serializable]
		[StructLayout(LayoutKind.Sequential)]
		public struct Vector3 : IEquatable<Vector3>
		{
			#region Fields

			/// <summary>
			/// The X component of the Vector3.
			/// </summary>
			public float X;

			/// <summary>
			/// The Y component of the Vector3.
			/// </summary>
			public float Y;

			/// <summary>
			/// The Z component of the Vector3.
			/// </summary>
			public float Z;

			#endregion

			#region Constructors

			/// <summary>
			/// Constructs a new instance.
			/// </summary>
			/// <param name="value">The value that will initialize this instance.</param>
			public Vector3(float value)
			{
				X = value;
				Y = value;
				Z = value;
			}

			/// <summary>
			/// Constructs a new Vector3.
			/// </summary>
			/// <param name="x">The x component of the Vector3.</param>
			/// <param name="y">The y component of the Vector3.</param>
			/// <param name="z">The z component of the Vector3.</param>
			public Vector3(float x, float y, float z)
			{
				X = x;
				Y = y;
				Z = z;
			}

			/// <summary>
			/// Constructs a new Vector3 from the given Vector2.
			/// </summary>
			/// <param name="v">The Vector2 to copy components from.</param>
			public Vector3(Vector2 v)
			{
				X = v.X;
				Y = v.Y;
				Z = 0.0f;
			}

			/// <summary>
			/// Constructs a new Vector3 from the given Vector3.
			/// </summary>
			/// <param name="v">The Vector3 to copy components from.</param>
			public Vector3(Vector3 v)
			{
				X = v.X;
				Y = v.Y;
				Z = v.Z;
			}

			/// <summary>
			/// Constructs a new Vector3 from the given Vector4.
			/// </summary>
			/// <param name="v">The Vector4 to copy components from.</param>
			public Vector3(Vector4 v)
			{
				X = v.X;
				Y = v.Y;
				Z = v.Z;
			}

			#endregion

			#region Public Members

			#region Instance

			#region public void Add()

			/// <summary>Add the Vector passed as parameter to this instance.</summary>
			/// <param name="right">Right operand. This parameter is only read from.</param>
			[Obsolete("Use static Add() method instead.")]
			public void Add(Vector3 right)
			{
				this.X += right.X;
				this.Y += right.Y;
				this.Z += right.Z;
			}

			/// <summary>Add the Vector passed as parameter to this instance.</summary>
			/// <param name="right">Right operand. This parameter is only read from.</param>
			[CLSCompliant(false)]
			[Obsolete("Use static Add() method instead.")]
			public void Add(ref Vector3 right)
			{
				this.X += right.X;
				this.Y += right.Y;
				this.Z += right.Z;
			}

			#endregion public void Add()

			#region public void Sub()

			/// <summary>Subtract the Vector passed as parameter from this instance.</summary>
			/// <param name="right">Right operand. This parameter is only read from.</param>
			[Obsolete("Use static Subtract() method instead.")]
			public void Sub(Vector3 right)
			{
				this.X -= right.X;
				this.Y -= right.Y;
				this.Z -= right.Z;
			}

			/// <summary>Subtract the Vector passed as parameter from this instance.</summary>
			/// <param name="right">Right operand. This parameter is only read from.</param>
			[CLSCompliant(false)]
			[Obsolete("Use static Subtract() method instead.")]
			public void Sub(ref Vector3 right)
			{
				this.X -= right.X;
				this.Y -= right.Y;
				this.Z -= right.Z;
			}

			#endregion public void Sub()

			#region public void Mult()

			/// <summary>Multiply this instance by a scalar.</summary>
			/// <param name="f">Scalar operand.</param>
			[Obsolete("Use static Multiply() method instead.")]
			public void Mult(float f)
			{
				this.X *= f;
				this.Y *= f;
				this.Z *= f;
			}

			#endregion public void Mult()

			#region public void Div()

			/// <summary>Divide this instance by a scalar.</summary>
			/// <param name="f">Scalar operand.</param>
			[Obsolete("Use static Divide() method instead.")]
			public void Div(float f)
			{
				float mult = 1.0f / f;
				this.X *= mult;
				this.Y *= mult;
				this.Z *= mult;
			}

			#endregion public void Div()

			#region public float Length

			/// <summary>
			/// Gets the length (magnitude) of the vector.
			/// </summary>
			/// <see cref="LengthFast"/>
			/// <seealso cref="LengthSquared"/>
			public float Length
			{
				get
				{
					return (float)System.Math.Sqrt(X * X + Y * Y + Z * Z);
				}
			}

			#endregion

			#region public float LengthFast

			///// <summary>
			///// Gets an approximation of the vector length (magnitude).
			///// </summary>
			///// <remarks>
			///// This property uses an approximation of the square root function to calculate vector magnitude, with
			///// an upper error bound of 0.001.
			///// </remarks>
			///// <see cref="Length"/>
			///// <seealso cref="LengthSquared"/>
			//public float LengthFast
			//{
			//    get
			//    {
			//        return 1.0f / MathHelper.InverseSqrtFast(X * X + Y * Y + Z * Z);
			//    }
			//}

			#endregion

			#region public float LengthSquared

			/// <summary>
			/// Gets the square of the vector length (magnitude).
			/// </summary>
			/// <remarks>
			/// This property avoids the costly square root operation required by the Length property. This makes it more suitable
			/// for comparisons.
			/// </remarks>
			/// <see cref="Length"/>
			/// <seealso cref="LengthFast"/>
			public float LengthSquared
			{
				get
				{
					return X * X + Y * Y + Z * Z;
				}
			}

			#endregion

			#region public void Normalize()

			/// <summary>
			/// Scales the Vector3 to unit length.
			/// </summary>
			public void Normalize()
			{
				float scale = 1.0f / this.Length;
				X *= scale;
				Y *= scale;
				Z *= scale;
			}

			#endregion

			#region public void NormalizeFast()

			///// <summary>
			///// Scales the Vector3 to approximately unit length.
			///// </summary>
			//public void NormalizeFast()
			//{
			//    float scale = MathHelper.InverseSqrtFast(X * X + Y * Y + Z * Z);
			//    X *= scale;
			//    Y *= scale;
			//    Z *= scale;
			//}

			#endregion

			#region public void Scale()

			/// <summary>
			/// Scales the current Vector3 by the given amounts.
			/// </summary>
			/// <param name="sx">The scale of the X component.</param>
			/// <param name="sy">The scale of the Y component.</param>
			/// <param name="sz">The scale of the Z component.</param>
			[Obsolete("Use static Multiply() method instead.")]
			public void Scale(float sx, float sy, float sz)
			{
				this.X = X * sx;
				this.Y = Y * sy;
				this.Z = Z * sz;
			}

			/// <summary>Scales this instance by the given parameter.</summary>
			/// <param name="scale">The scaling of the individual components.</param>
			[Obsolete("Use static Multiply() method instead.")]
			public void Scale(Vector3 scale)
			{
				this.X *= scale.X;
				this.Y *= scale.Y;
				this.Z *= scale.Z;
			}

			/// <summary>Scales this instance by the given parameter.</summary>
			/// <param name="scale">The scaling of the individual components.</param>
			[CLSCompliant(false)]
			[Obsolete("Use static Multiply() method instead.")]
			public void Scale(ref Vector3 scale)
			{
				this.X *= scale.X;
				this.Y *= scale.Y;
				this.Z *= scale.Z;
			}

			#endregion public void Scale()

			#endregion

			#region Static

			#region Fields

			/// <summary>
			/// Defines a unit-length Vector3 that points towards the X-axis.
			/// </summary>
			public static readonly Vector3 UnitX = new Vector3(1, 0, 0);

			/// <summary>
			/// Defines a unit-length Vector3 that points towards the Y-axis.
			/// </summary>
			public static readonly Vector3 UnitY = new Vector3(0, 1, 0);

			/// <summary>
			/// /// Defines a unit-length Vector3 that points towards the Z-axis.
			/// </summary>
			public static readonly Vector3 UnitZ = new Vector3(0, 0, 1);

			/// <summary>
			/// Defines a zero-length Vector3.
			/// </summary>
			public static readonly Vector3 Zero = new Vector3(0, 0, 0);

			/// <summary>
			/// Defines an instance with all components set to 1.
			/// </summary>
			public static readonly Vector3 One = new Vector3(1, 1, 1);

			/// <summary>
			/// Defines the size of the Vector3 struct in bytes.
			/// </summary>
			public static readonly int SizeInBytes = Marshal.SizeOf(new Vector3());

			#endregion

			#region Obsolete

			#region Sub

			/// <summary>
			/// Subtract one Vector from another
			/// </summary>
			/// <param name="a">First operand</param>
			/// <param name="b">Second operand</param>
			/// <returns>Result of subtraction</returns>
			[Obsolete("Use static Subtract() method instead.")]
			public static Vector3 Sub(Vector3 a, Vector3 b)
			{
				a.X -= b.X;
				a.Y -= b.Y;
				a.Z -= b.Z;
				return a;
			}

			/// <summary>
			/// Subtract one Vector from another
			/// </summary>
			/// <param name="a">First operand</param>
			/// <param name="b">Second operand</param>
			/// <param name="result">Result of subtraction</param>
			[Obsolete("Use static Subtract() method instead.")]
			public static void Sub(ref Vector3 a, ref Vector3 b, out Vector3 result)
			{
				result.X = a.X - b.X;
				result.Y = a.Y - b.Y;
				result.Z = a.Z - b.Z;
			}

			#endregion

			#region Mult

			/// <summary>
			/// Multiply a vector and a scalar
			/// </summary>
			/// <param name="a">Vector operand</param>
			/// <param name="f">Scalar operand</param>
			/// <returns>Result of the multiplication</returns>
			[Obsolete("Use static Multiply() method instead.")]
			public static Vector3 Mult(Vector3 a, float f)
			{
				a.X *= f;
				a.Y *= f;
				a.Z *= f;
				return a;
			}

			/// <summary>
			/// Multiply a vector and a scalar
			/// </summary>
			/// <param name="a">Vector operand</param>
			/// <param name="f">Scalar operand</param>
			/// <param name="result">Result of the multiplication</param>
			[Obsolete("Use static Multiply() method instead.")]
			public static void Mult(ref Vector3 a, float f, out Vector3 result)
			{
				result.X = a.X * f;
				result.Y = a.Y * f;
				result.Z = a.Z * f;
			}

			#endregion

			#region Div

			/// <summary>
			/// Divide a vector by a scalar
			/// </summary>
			/// <param name="a">Vector operand</param>
			/// <param name="f">Scalar operand</param>
			/// <returns>Result of the division</returns>
			[Obsolete("Use static Divide() method instead.")]
			public static Vector3 Div(Vector3 a, float f)
			{
				float mult = 1.0f / f;
				a.X *= mult;
				a.Y *= mult;
				a.Z *= mult;
				return a;
			}

			/// <summary>
			/// Divide a vector by a scalar
			/// </summary>
			/// <param name="a">Vector operand</param>
			/// <param name="f">Scalar operand</param>
			/// <param name="result">Result of the division</param>
			[Obsolete("Use static Divide() method instead.")]
			public static void Div(ref Vector3 a, float f, out Vector3 result)
			{
				float mult = 1.0f / f;
				result.X = a.X * mult;
				result.Y = a.Y * mult;
				result.Z = a.Z * mult;
			}

			#endregion

			#endregion

			#region Add

			/// <summary>
			/// Adds two vectors.
			/// </summary>
			/// <param name="a">Left operand.</param>
			/// <param name="b">Right operand.</param>
			/// <returns>Result of operation.</returns>
			public static Vector3 Add(Vector3 a, Vector3 b)
			{
				Add(ref a, ref b, out a);
				return a;
			}

			/// <summary>
			/// Adds two vectors.
			/// </summary>
			/// <param name="a">Left operand.</param>
			/// <param name="b">Right operand.</param>
			/// <param name="result">Result of operation.</param>
			public static void Add(ref Vector3 a, ref Vector3 b, out Vector3 result)
			{
				result = new Vector3(a.X + b.X, a.Y + b.Y, a.Z + b.Z);
			}

			#endregion

			#region Subtract

			/// <summary>
			/// Subtract one Vector from another
			/// </summary>
			/// <param name="a">First operand</param>
			/// <param name="b">Second operand</param>
			/// <returns>Result of subtraction</returns>
			public static Vector3 Subtract(Vector3 a, Vector3 b)
			{
				Subtract(ref a, ref b, out a);
				return a;
			}

			/// <summary>
			/// Subtract one Vector from another
			/// </summary>
			/// <param name="a">First operand</param>
			/// <param name="b">Second operand</param>
			/// <param name="result">Result of subtraction</param>
			public static void Subtract(ref Vector3 a, ref Vector3 b, out Vector3 result)
			{
				result = new Vector3(a.X - b.X, a.Y - b.Y, a.Z - b.Z);
			}

			#endregion

			#region Multiply

			/// <summary>
			/// Multiplies a vector by a scalar.
			/// </summary>
			/// <param name="vector">Left operand.</param>
			/// <param name="scale">Right operand.</param>
			/// <returns>Result of the operation.</returns>
			public static Vector3 Multiply(Vector3 vector, float scale)
			{
				Multiply(ref vector, scale, out vector);
				return vector;
			}

			/// <summary>
			/// Multiplies a vector by a scalar.
			/// </summary>
			/// <param name="vector">Left operand.</param>
			/// <param name="scale">Right operand.</param>
			/// <param name="result">Result of the operation.</param>
			public static void Multiply(ref Vector3 vector, float scale, out Vector3 result)
			{
				result = new Vector3(vector.X * scale, vector.Y * scale, vector.Z * scale);
			}

			/// <summary>
			/// Multiplies a vector by the components a vector (scale).
			/// </summary>
			/// <param name="vector">Left operand.</param>
			/// <param name="scale">Right operand.</param>
			/// <returns>Result of the operation.</returns>
			public static Vector3 Multiply(Vector3 vector, Vector3 scale)
			{
				Multiply(ref vector, ref scale, out vector);
				return vector;
			}

			/// <summary>
			/// Multiplies a vector by the components of a vector (scale).
			/// </summary>
			/// <param name="vector">Left operand.</param>
			/// <param name="scale">Right operand.</param>
			/// <param name="result">Result of the operation.</param>
			public static void Multiply(ref Vector3 vector, ref Vector3 scale, out Vector3 result)
			{
				result = new Vector3(vector.X * scale.X, vector.Y * scale.Y, vector.Z * scale.Z);
			}

			#endregion

			#region Divide

			/// <summary>
			/// Divides a vector by a scalar.
			/// </summary>
			/// <param name="vector">Left operand.</param>
			/// <param name="scale">Right operand.</param>
			/// <returns>Result of the operation.</returns>
			public static Vector3 Divide(Vector3 vector, float scale)
			{
				Divide(ref vector, scale, out vector);
				return vector;
			}

			/// <summary>
			/// Divides a vector by a scalar.
			/// </summary>
			/// <param name="vector">Left operand.</param>
			/// <param name="scale">Right operand.</param>
			/// <param name="result">Result of the operation.</param>
			public static void Divide(ref Vector3 vector, float scale, out Vector3 result)
			{
				Multiply(ref vector, 1 / scale, out result);
			}

			/// <summary>
			/// Divides a vector by the components of a vector (scale).
			/// </summary>
			/// <param name="vector">Left operand.</param>
			/// <param name="scale">Right operand.</param>
			/// <returns>Result of the operation.</returns>
			public static Vector3 Divide(Vector3 vector, Vector3 scale)
			{
				Divide(ref vector, ref scale, out vector);
				return vector;
			}

			/// <summary>
			/// Divide a vector by the components of a vector (scale).
			/// </summary>
			/// <param name="vector">Left operand.</param>
			/// <param name="scale">Right operand.</param>
			/// <param name="result">Result of the operation.</param>
			public static void Divide(ref Vector3 vector, ref Vector3 scale, out Vector3 result)
			{
				result = new Vector3(vector.X / scale.X, vector.Y / scale.Y, vector.Z / scale.Z);
			}

			#endregion

			#region ComponentMin

			/// <summary>
			/// Calculate the component-wise minimum of two vectors
			/// </summary>
			/// <param name="a">First operand</param>
			/// <param name="b">Second operand</param>
			/// <returns>The component-wise minimum</returns>
			public static Vector3 ComponentMin(Vector3 a, Vector3 b)
			{
				a.X = a.X < b.X ? a.X : b.X;
				a.Y = a.Y < b.Y ? a.Y : b.Y;
				a.Z = a.Z < b.Z ? a.Z : b.Z;
				return a;
			}

			/// <summary>
			/// Calculate the component-wise minimum of two vectors
			/// </summary>
			/// <param name="a">First operand</param>
			/// <param name="b">Second operand</param>
			/// <param name="result">The component-wise minimum</param>
			public static void ComponentMin(ref Vector3 a, ref Vector3 b, out Vector3 result)
			{
				result.X = a.X < b.X ? a.X : b.X;
				result.Y = a.Y < b.Y ? a.Y : b.Y;
				result.Z = a.Z < b.Z ? a.Z : b.Z;
			}

			#endregion

			#region ComponentMax

			/// <summary>
			/// Calculate the component-wise maximum of two vectors
			/// </summary>
			/// <param name="a">First operand</param>
			/// <param name="b">Second operand</param>
			/// <returns>The component-wise maximum</returns>
			public static Vector3 ComponentMax(Vector3 a, Vector3 b)
			{
				a.X = a.X > b.X ? a.X : b.X;
				a.Y = a.Y > b.Y ? a.Y : b.Y;
				a.Z = a.Z > b.Z ? a.Z : b.Z;
				return a;
			}

			/// <summary>
			/// Calculate the component-wise maximum of two vectors
			/// </summary>
			/// <param name="a">First operand</param>
			/// <param name="b">Second operand</param>
			/// <param name="result">The component-wise maximum</param>
			public static void ComponentMax(ref Vector3 a, ref Vector3 b, out Vector3 result)
			{
				result.X = a.X > b.X ? a.X : b.X;
				result.Y = a.Y > b.Y ? a.Y : b.Y;
				result.Z = a.Z > b.Z ? a.Z : b.Z;
			}

			#endregion

			#region Min

			/// <summary>
			/// Returns the Vector3 with the minimum magnitude
			/// </summary>
			/// <param name="left">Left operand</param>
			/// <param name="right">Right operand</param>
			/// <returns>The minimum Vector3</returns>
			public static Vector3 Min(Vector3 left, Vector3 right)
			{
				return left.LengthSquared < right.LengthSquared ? left : right;
			}

			#endregion

			#region Max

			/// <summary>
			/// Returns the Vector3 with the minimum magnitude
			/// </summary>
			/// <param name="left">Left operand</param>
			/// <param name="right">Right operand</param>
			/// <returns>The minimum Vector3</returns>
			public static Vector3 Max(Vector3 left, Vector3 right)
			{
				return left.LengthSquared >= right.LengthSquared ? left : right;
			}

			#endregion

			#region Clamp

			/// <summary>
			/// Clamp a vector to the given minimum and maximum vectors
			/// </summary>
			/// <param name="vec">Input vector</param>
			/// <param name="min">Minimum vector</param>
			/// <param name="max">Maximum vector</param>
			/// <returns>The clamped vector</returns>
			public static Vector3 Clamp(Vector3 vec, Vector3 min, Vector3 max)
			{
				vec.X = vec.X < min.X ? min.X : vec.X > max.X ? max.X : vec.X;
				vec.Y = vec.Y < min.Y ? min.Y : vec.Y > max.Y ? max.Y : vec.Y;
				vec.Z = vec.Z < min.Z ? min.Z : vec.Z > max.Z ? max.Z : vec.Z;
				return vec;
			}

			/// <summary>
			/// Clamp a vector to the given minimum and maximum vectors
			/// </summary>
			/// <param name="vec">Input vector</param>
			/// <param name="min">Minimum vector</param>
			/// <param name="max">Maximum vector</param>
			/// <param name="result">The clamped vector</param>
			public static void Clamp(ref Vector3 vec, ref Vector3 min, ref Vector3 max, out Vector3 result)
			{
				result.X = vec.X < min.X ? min.X : vec.X > max.X ? max.X : vec.X;
				result.Y = vec.Y < min.Y ? min.Y : vec.Y > max.Y ? max.Y : vec.Y;
				result.Z = vec.Z < min.Z ? min.Z : vec.Z > max.Z ? max.Z : vec.Z;
			}

			#endregion

			#region Normalize

			/// <summary>
			/// Scale a vector to unit length
			/// </summary>
			/// <param name="vec">The input vector</param>
			/// <returns>The normalized vector</returns>
			public static Vector3 Normalize(Vector3 vec)
			{
				float scale = 1.0f / vec.Length;
				vec.X *= scale;
				vec.Y *= scale;
				vec.Z *= scale;
				return vec;
			}

			/// <summary>
			/// Scale a vector to unit length
			/// </summary>
			/// <param name="vec">The input vector</param>
			/// <param name="result">The normalized vector</param>
			public static void Normalize(ref Vector3 vec, out Vector3 result)
			{
				float scale = 1.0f / vec.Length;
				result.X = vec.X * scale;
				result.Y = vec.Y * scale;
				result.Z = vec.Z * scale;
			}

			#endregion

			#region NormalizeFast

			///// <summary>
			///// Scale a vector to approximately unit length
			///// </summary>
			///// <param name="vec">The input vector</param>
			///// <returns>The normalized vector</returns>
			//public static Vector3 NormalizeFast(Vector3 vec)
			//{
			//    float scale = MathHelper.InverseSqrtFast(vec.X * vec.X + vec.Y * vec.Y + vec.Z * vec.Z);
			//    vec.X *= scale;
			//    vec.Y *= scale;
			//    vec.Z *= scale;
			//    return vec;
			//}

			///// <summary>
			///// Scale a vector to approximately unit length
			///// </summary>
			///// <param name="vec">The input vector</param>
			///// <param name="result">The normalized vector</param>
			//public static void NormalizeFast(ref Vector3 vec, out Vector3 result)
			//{
			//    float scale = MathHelper.InverseSqrtFast(vec.X * vec.X + vec.Y * vec.Y + vec.Z * vec.Z);
			//    result.X = vec.X * scale;
			//    result.Y = vec.Y * scale;
			//    result.Z = vec.Z * scale;
			//}

			#endregion

			#region Dot

			/// <summary>
			/// Calculate the dot (scalar) product of two vectors
			/// </summary>
			/// <param name="left">First operand</param>
			/// <param name="right">Second operand</param>
			/// <returns>The dot product of the two inputs</returns>
			public static float Dot(Vector3 left, Vector3 right)
			{
				return left.X * right.X + left.Y * right.Y + left.Z * right.Z;
			}

			/// <summary>
			/// Calculate the dot (scalar) product of two vectors
			/// </summary>
			/// <param name="left">First operand</param>
			/// <param name="right">Second operand</param>
			/// <param name="result">The dot product of the two inputs</param>
			public static void Dot(ref Vector3 left, ref Vector3 right, out float result)
			{
				result = left.X * right.X + left.Y * right.Y + left.Z * right.Z;
			}

			#endregion

			#region Cross

			/// <summary>
			/// Caclulate the cross (vector) product of two vectors
			/// </summary>
			/// <param name="left">First operand</param>
			/// <param name="right">Second operand</param>
			/// <returns>The cross product of the two inputs</returns>
			public static Vector3 Cross(Vector3 left, Vector3 right)
			{
				Vector3 result;
				Cross(ref left, ref right, out result);
				return result;
			}

			/// <summary>
			/// Caclulate the cross (vector) product of two vectors
			/// </summary>
			/// <param name="left">First operand</param>
			/// <param name="right">Second operand</param>
			/// <returns>The cross product of the two inputs</returns>
			/// <param name="result">The cross product of the two inputs</param>
			public static void Cross(ref Vector3 left, ref Vector3 right, out Vector3 result)
			{
				result = new Vector3(left.Y * right.Z - left.Z * right.Y,
					left.Z * right.X - left.X * right.Z,
					left.X * right.Y - left.Y * right.X);
			}

			#endregion

			#region Lerp

			/// <summary>
			/// Returns a new Vector that is the linear blend of the 2 given Vectors
			/// </summary>
			/// <param name="a">First input vector</param>
			/// <param name="b">Second input vector</param>
			/// <param name="blend">The blend factor. a when blend=0, b when blend=1.</param>
			/// <returns>a when blend=0, b when blend=1, and a linear combination otherwise</returns>
			public static Vector3 Lerp(Vector3 a, Vector3 b, float blend)
			{
				a.X = blend * (b.X - a.X) + a.X;
				a.Y = blend * (b.Y - a.Y) + a.Y;
				a.Z = blend * (b.Z - a.Z) + a.Z;
				return a;
			}

			/// <summary>
			/// Returns a new Vector that is the linear blend of the 2 given Vectors
			/// </summary>
			/// <param name="a">First input vector</param>
			/// <param name="b">Second input vector</param>
			/// <param name="blend">The blend factor. a when blend=0, b when blend=1.</param>
			/// <param name="result">a when blend=0, b when blend=1, and a linear combination otherwise</param>
			public static void Lerp(ref Vector3 a, ref Vector3 b, float blend, out Vector3 result)
			{
				result.X = blend * (b.X - a.X) + a.X;
				result.Y = blend * (b.Y - a.Y) + a.Y;
				result.Z = blend * (b.Z - a.Z) + a.Z;
			}

			#endregion

			#region Barycentric

			/// <summary>
			/// Interpolate 3 Vectors using Barycentric coordinates
			/// </summary>
			/// <param name="a">First input Vector</param>
			/// <param name="b">Second input Vector</param>
			/// <param name="c">Third input Vector</param>
			/// <param name="u">First Barycentric Coordinate</param>
			/// <param name="v">Second Barycentric Coordinate</param>
			/// <returns>a when u=v=0, b when u=1,v=0, c when u=0,v=1, and a linear combination of a,b,c otherwise</returns>
			public static Vector3 BaryCentric(Vector3 a, Vector3 b, Vector3 c, float u, float v)
			{
				return a + u * (b - a) + v * (c - a);
			}

			/// <summary>Interpolate 3 Vectors using Barycentric coordinates</summary>
			/// <param name="a">First input Vector.</param>
			/// <param name="b">Second input Vector.</param>
			/// <param name="c">Third input Vector.</param>
			/// <param name="u">First Barycentric Coordinate.</param>
			/// <param name="v">Second Barycentric Coordinate.</param>
			/// <param name="result">Output Vector. a when u=v=0, b when u=1,v=0, c when u=0,v=1, and a linear combination of a,b,c otherwise</param>
			public static void BaryCentric(ref Vector3 a, ref Vector3 b, ref Vector3 c, float u, float v, out Vector3 result)
			{
				result = a; // copy

				Vector3 temp = b; // copy
				Subtract(ref temp, ref a, out temp);
				Multiply(ref temp, u, out temp);
				Add(ref result, ref temp, out result);

				temp = c; // copy
				Subtract(ref temp, ref a, out temp);
				Multiply(ref temp, v, out temp);
				Add(ref result, ref temp, out result);
			}

			#endregion

			#region Transform

			/// <summary>Transform a direction vector by the given Matrix
			/// Assumes the matrix has a bottom row of (0,0,0,1), that is the translation part is ignored.
			/// </summary>
			/// <param name="vec">The vector to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <returns>The transformed vector</returns>
			public static Vector3 TransformVector(Vector3 vec, Matrix4 mat)
			{
				Vector3 v;
				v.X = Vector3.Dot(vec, new Vector3(mat.Column0));
				v.Y = Vector3.Dot(vec, new Vector3(mat.Column1));
				v.Z = Vector3.Dot(vec, new Vector3(mat.Column2));
				return v;
			}

			/// <summary>Transform a direction vector by the given Matrix
			/// Assumes the matrix has a bottom row of (0,0,0,1), that is the translation part is ignored.
			/// </summary>
			/// <param name="vec">The vector to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <param name="result">The transformed vector</param>
			public static void TransformVector(ref Vector3 vec, ref Matrix4 mat, out Vector3 result)
			{
				result.X = vec.X * mat.Row0.X +
						   vec.Y * mat.Row1.X +
						   vec.Z * mat.Row2.X;

				result.Y = vec.X * mat.Row0.Y +
						   vec.Y * mat.Row1.Y +
						   vec.Z * mat.Row2.Y;

				result.Z = vec.X * mat.Row0.Z +
						   vec.Y * mat.Row1.Z +
						   vec.Z * mat.Row2.Z;
			}

			/// <summary>Transform a Normal by the given Matrix</summary>
			/// <remarks>
			/// This calculates the inverse of the given matrix, use TransformNormalInverse if you
			/// already have the inverse to avoid this extra calculation
			/// </remarks>
			/// <param name="norm">The normal to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <returns>The transformed normal</returns>
			public static Vector3 TransformNormal(Vector3 norm, Matrix4 mat)
			{
				mat.Invert();
				return TransformNormalInverse(norm, mat);
			}

			/// <summary>Transform a Normal by the given Matrix</summary>
			/// <remarks>
			/// This calculates the inverse of the given matrix, use TransformNormalInverse if you
			/// already have the inverse to avoid this extra calculation
			/// </remarks>
			/// <param name="norm">The normal to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <param name="result">The transformed normal</param>
			public static void TransformNormal(ref Vector3 norm, ref Matrix4 mat, out Vector3 result)
			{
				Matrix4 Inverse = Matrix4.Invert(mat);
				Vector3.TransformNormalInverse(ref norm, ref Inverse, out result);
			}

			/// <summary>Transform a Normal by the (transpose of the) given Matrix</summary>
			/// <remarks>
			/// This version doesn't calculate the inverse matrix.
			/// Use this version if you already have the inverse of the desired transform to hand
			/// </remarks>
			/// <param name="norm">The normal to transform</param>
			/// <param name="invMat">The inverse of the desired transformation</param>
			/// <returns>The transformed normal</returns>
			public static Vector3 TransformNormalInverse(Vector3 norm, Matrix4 invMat)
			{
				Vector3 n;
				n.X = Vector3.Dot(norm, new Vector3(invMat.Row0));
				n.Y = Vector3.Dot(norm, new Vector3(invMat.Row1));
				n.Z = Vector3.Dot(norm, new Vector3(invMat.Row2));
				return n;
			}

			/// <summary>Transform a Normal by the (transpose of the) given Matrix</summary>
			/// <remarks>
			/// This version doesn't calculate the inverse matrix.
			/// Use this version if you already have the inverse of the desired transform to hand
			/// </remarks>
			/// <param name="norm">The normal to transform</param>
			/// <param name="invMat">The inverse of the desired transformation</param>
			/// <param name="result">The transformed normal</param>
			public static void TransformNormalInverse(ref Vector3 norm, ref Matrix4 invMat, out Vector3 result)
			{
				result.X = norm.X * invMat.Row0.X +
						   norm.Y * invMat.Row0.Y +
						   norm.Z * invMat.Row0.Z;

				result.Y = norm.X * invMat.Row1.X +
						   norm.Y * invMat.Row1.Y +
						   norm.Z * invMat.Row1.Z;

				result.Z = norm.X * invMat.Row2.X +
						   norm.Y * invMat.Row2.Y +
						   norm.Z * invMat.Row2.Z;
			}

			/// <summary>Transform a Position by the given Matrix</summary>
			/// <param name="pos">The position to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <returns>The transformed position</returns>
			public static Vector3 TransformPosition(Vector3 pos, Matrix4 mat)
			{
				Vector3 p;
				p.X = Vector3.Dot(pos, new Vector3(mat.Column0)) + mat.Row3.X;
				p.Y = Vector3.Dot(pos, new Vector3(mat.Column1)) + mat.Row3.Y;
				p.Z = Vector3.Dot(pos, new Vector3(mat.Column2)) + mat.Row3.Z;
				return p;
			}

			/// <summary>Transform a Position by the given Matrix</summary>
			/// <param name="pos">The position to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <param name="result">The transformed position</param>
			public static void TransformPosition(ref Vector3 pos, ref Matrix4 mat, out Vector3 result)
			{
				result.X = pos.X * mat.Row0.X +
						   pos.Y * mat.Row1.X +
						   pos.Z * mat.Row2.X +
						   mat.Row3.X;

				result.Y = pos.X * mat.Row0.Y +
						   pos.Y * mat.Row1.Y +
						   pos.Z * mat.Row2.Y +
						   mat.Row3.Y;

				result.Z = pos.X * mat.Row0.Z +
						   pos.Y * mat.Row1.Z +
						   pos.Z * mat.Row2.Z +
						   mat.Row3.Z;
			}

			/// <summary>Transform a Vector by the given Matrix</summary>
			/// <param name="vec">The vector to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <returns>The transformed vector</returns>
			public static Vector3 Transform(Vector3 vec, Matrix4 mat)
			{
				Vector3 result;
				Transform(ref vec, ref mat, out result);
				return result;
			}

			/// <summary>Transform a Vector by the given Matrix</summary>
			/// <param name="vec">The vector to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <param name="result">The transformed vector</param>
			public static void Transform(ref Vector3 vec, ref Matrix4 mat, out Vector3 result)
			{
				Vector4 v4 = new Vector4(vec.X, vec.Y, vec.Z, 1.0f);
				Vector4.Transform(ref v4, ref mat, out v4);
				result = v4.Xyz;
			}

			/// <summary>
			/// Transforms a vector by a quaternion rotation.
			/// </summary>
			/// <param name="vec">The vector to transform.</param>
			/// <param name="quat">The quaternion to rotate the vector by.</param>
			/// <returns>The result of the operation.</returns>
			public static Vector3 Transform(Vector3 vec, Quaternion quat)
			{
				Vector3 result;
				Transform(ref vec, ref quat, out result);
				return result;
			}

			/// <summary>
			/// Transforms a vector by a quaternion rotation.
			/// </summary>
			/// <param name="vec">The vector to transform.</param>
			/// <param name="quat">The quaternion to rotate the vector by.</param>
			/// <param name="result">The result of the operation.</param>
			public static void Transform(ref Vector3 vec, ref Quaternion quat, out Vector3 result)
			{
				// Since vec.W == 0, we can optimize quat * vec * quat^-1 as follows:
				// vec + 2.0 * cross(quat.xyz, cross(quat.xyz, vec) + quat.w * vec)
				Vector3 xyz = quat.Xyz, temp, temp2;
				Vector3.Cross(ref xyz, ref vec, out temp);
				Vector3.Multiply(ref vec, quat.W, out temp2);
				Vector3.Add(ref temp, ref temp2, out temp);
				Vector3.Cross(ref xyz, ref temp, out temp);
				Vector3.Multiply(ref temp, 2, out temp);
				Vector3.Add(ref vec, ref temp, out result);
			}

			/// <summary>Transform a Vector3 by the given Matrix, and project the resulting Vector4 back to a Vector3</summary>
			/// <param name="vec">The vector to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <returns>The transformed vector</returns>
			public static Vector3 TransformPerspective(Vector3 vec, Matrix4 mat)
			{
				Vector3 result;
				TransformPerspective(ref vec, ref mat, out result);
				return result;
			}

			/// <summary>Transform a Vector3 by the given Matrix, and project the resulting Vector4 back to a Vector3</summary>
			/// <param name="vec">The vector to transform</param>
			/// <param name="mat">The desired transformation</param>
			/// <param name="result">The transformed vector</param>
			public static void TransformPerspective(ref Vector3 vec, ref Matrix4 mat, out Vector3 result)
			{
				Vector4 v = new Vector4(vec, 1);
				Vector4.Transform(ref v, ref mat, out v);
				result.X = v.X / v.W;
				result.Y = v.Y / v.W;
				result.Z = v.Z / v.W;
			}

			#endregion

			#region CalculateAngle

			/// <summary>
			/// Calculates the angle (in radians) between two vectors.
			/// </summary>
			/// <param name="first">The first vector.</param>
			/// <param name="second">The second vector.</param>
			/// <returns>Angle (in radians) between the vectors.</returns>
			/// <remarks>Note that the returned angle is never bigger than the constant Pi.</remarks>
			public static float CalculateAngle(Vector3 first, Vector3 second)
			{
				return (float)System.Math.Acos((Vector3.Dot(first, second)) / (first.Length * second.Length));
			}

			/// <summary>Calculates the angle (in radians) between two vectors.</summary>
			/// <param name="first">The first vector.</param>
			/// <param name="second">The second vector.</param>
			/// <param name="result">Angle (in radians) between the vectors.</param>
			/// <remarks>Note that the returned angle is never bigger than the constant Pi.</remarks>
			public static void CalculateAngle(ref Vector3 first, ref Vector3 second, out float result)
			{
				float temp;
				Vector3.Dot(ref first, ref second, out temp);
				result = (float)System.Math.Acos(temp / (first.Length * second.Length));
			}

			#endregion

			#endregion

			#region Swizzle

			/// <summary>
			/// Gets or sets an OpenTK.Vector2 with the X and Y components of this instance.
			/// </summary>
			[XmlIgnore]
			public Vector2 Xy { get { return new Vector2(X, Y); } set { X = value.X; Y = value.Y; } }

			#endregion

			#region Operators

			/// <summary>
			/// Adds two instances.
			/// </summary>
			/// <param name="left">The first instance.</param>
			/// <param name="right">The second instance.</param>
			/// <returns>The result of the calculation.</returns>
			public static Vector3 operator +(Vector3 left, Vector3 right)
			{
				left.X += right.X;
				left.Y += right.Y;
				left.Z += right.Z;
				return left;
			}

			/// <summary>
			/// Subtracts two instances.
			/// </summary>
			/// <param name="left">The first instance.</param>
			/// <param name="right">The second instance.</param>
			/// <returns>The result of the calculation.</returns>
			public static Vector3 operator -(Vector3 left, Vector3 right)
			{
				left.X -= right.X;
				left.Y -= right.Y;
				left.Z -= right.Z;
				return left;
			}

			/// <summary>
			/// Negates an instance.
			/// </summary>
			/// <param name="vec">The instance.</param>
			/// <returns>The result of the calculation.</returns>
			public static Vector3 operator -(Vector3 vec)
			{
				vec.X = -vec.X;
				vec.Y = -vec.Y;
				vec.Z = -vec.Z;
				return vec;
			}

			/// <summary>
			/// Multiplies an instance by a scalar.
			/// </summary>
			/// <param name="vec">The instance.</param>
			/// <param name="scale">The scalar.</param>
			/// <returns>The result of the calculation.</returns>
			public static Vector3 operator *(Vector3 vec, float scale)
			{
				vec.X *= scale;
				vec.Y *= scale;
				vec.Z *= scale;
				return vec;
			}

			/// <summary>
			/// Multiplies an instance by a scalar.
			/// </summary>
			/// <param name="scale">The scalar.</param>
			/// <param name="vec">The instance.</param>
			/// <returns>The result of the calculation.</returns>
			public static Vector3 operator *(float scale, Vector3 vec)
			{
				vec.X *= scale;
				vec.Y *= scale;
				vec.Z *= scale;
				return vec;
			}

			/// <summary>
			/// Divides an instance by a scalar.
			/// </summary>
			/// <param name="vec">The instance.</param>
			/// <param name="scale">The scalar.</param>
			/// <returns>The result of the calculation.</returns>
			public static Vector3 operator /(Vector3 vec, float scale)
			{
				float mult = 1.0f / scale;
				vec.X *= mult;
				vec.Y *= mult;
				vec.Z *= mult;
				return vec;
			}

			/// <summary>
			/// Compares two instances for equality.
			/// </summary>
			/// <param name="left">The first instance.</param>
			/// <param name="right">The second instance.</param>
			/// <returns>True, if left equals right; false otherwise.</returns>
			public static bool operator ==(Vector3 left, Vector3 right)
			{
				return left.Equals(right);
			}

			/// <summary>
			/// Compares two instances for inequality.
			/// </summary>
			/// <param name="left">The first instance.</param>
			/// <param name="right">The second instance.</param>
			/// <returns>True, if left does not equa lright; false otherwise.</returns>
			public static bool operator !=(Vector3 left, Vector3 right)
			{
				return !left.Equals(right);
			}

			#endregion

			#region Overrides

			#region public override string ToString()

			/// <summary>
			/// Returns a System.String that represents the current Vector3.
			/// </summary>
			/// <returns></returns>
			public override string ToString()
			{
				return String.Format("({0}, {1}, {2})", X, Y, Z);
			}

			#endregion

			#region public override int GetHashCode()

			/// <summary>
			/// Returns the hashcode for this instance.
			/// </summary>
			/// <returns>A System.Int32 containing the unique hashcode for this instance.</returns>
			public override int GetHashCode()
			{
				return X.GetHashCode() ^ Y.GetHashCode() ^ Z.GetHashCode();
			}

			#endregion

			#region public override bool Equals(object obj)

			/// <summary>
			/// Indicates whether this instance and a specified object are equal.
			/// </summary>
			/// <param name="obj">The object to compare to.</param>
			/// <returns>True if the instances are equal; false otherwise.</returns>
			public override bool Equals(object obj)
			{
				if (!(obj is Vector3))
					return false;

				return this.Equals((Vector3)obj);
			}

			#endregion

			#endregion

			#endregion

			#region IEquatable<Vector3> Members

			/// <summary>Indicates whether the current vector is equal to another vector.</summary>
			/// <param name="other">A vector to compare with this vector.</param>
			/// <returns>true if the current vector is equal to the vector parameter; otherwise, false.</returns>
			public bool Equals(Vector3 other)
			{
				return
					X == other.X &&
					Y == other.Y &&
					Z == other.Z;
			}

			#endregion
		}

}
